In recent years, it has been said that owing to the influence of chemical treatment such as hair coloring or physical treatment by blow drying, cuticles on the hair surface peel off or the hair becomes porous by the efflux of lipids from the inside of the hair and as a result, the hair inevitably becomes excessively dry, resistant to finger combing, difficult to style and is unmanageable and lusterless.
Examples of commercially available leave-on hair cosmetic compositions mainly used now include emulsion type products such as hair cream having wax, higher alcohol and surfactant to provide the hair with manageability and protect the hair from excessive drying; and gel products having a film forming polymer (set polymer) incorporated therein. Such hair cosmetic compositions can temporarily overcome the problems such as poor manageability and excessive dryness by causing an oil or fat or a polymer to adhere to the hair surface, thereby forming a film structure, but cannot fundamentally improve the hair luster or manageability.
Some hair cosmetic compositions for improving the hair quality are known. Of these, compositions using a specific organic acid and organic solvent are known as those using a technology intended to improve hair quality by acting on the inside of the hair (refer to, for example, JP-A-1995-112921, JP-A-1994-172131, JP-A-1997-301831 and JP-A-1994-298625). These compositions promote manageability of the hair by softening the hair which is stiff and therefore, hard to handle.